Lightning involves immense energy release during atmospheric electrical discharges. The air around a lightning flash can heat rapidly to temperatures reaching approximately 50,000 degrees Fahrenheit, which is hotter than the surface of the sun. A single lightning bolt can contain up to a billion volts and 100,000 or more amperes of electricity. The energy released typically averages between 200 megajoules and 7 gigajoules.
Impact on People
Lightning can injure humans through various mechanisms, not just direct contact. A direct strike occurs when a person becomes part of the main lightning discharge channel, often in open areas. Side flashes happen when lightning strikes a nearby taller object, like a tree, and a portion of the current jumps to a person, often those seeking shelter. Ground current is a common cause of injury, as energy spreads outward along the ground from a strike point, affecting anyone within the electrified area. Conduction also poses a risk, with lightning traveling through metal wires, plumbing, or other conductive surfaces that people might be touching.
Cardiac arrest is a common and often immediate cause of death, typically resulting from the heart stopping (asystole) or experiencing irregular rhythms. Even if the heart spontaneously resumes beating, respiratory arrest can be more prolonged. Neurological damage can lead to brain injuries, nerve damage, and conditions like posthypoxic encephalopathy or intracranial hemorrhage. Survivors may experience chronic issues such as cognitive impairment, memory problems, personality changes, and persistent headaches.
Burns from lightning are frequently superficial, appearing as linear or punctate marks, or unique fern-like patterns known as Lichtenberg figures. These external burns are often caused by the rapid heating of moisture on the skin or contact with heated metallic objects. Internal burns are less common directly from lightning due to the brief duration of exposure. Other potential injuries include:
- Blunt force trauma (if thrown by the strike’s force)
- Hearing loss and ruptured eardrums (from the shockwave)
- Muscle soreness
- Dizziness
- Balance problems
Damage to Structures and Infrastructure
Lightning inflicts substantial physical damage on buildings and other structures. The extreme heat generated by a lightning strike can easily ignite flammable materials such as wood, insulation, and gas lines, leading to fires. These fires can spread rapidly, potentially consuming entire structures, and may smolder for hours undetected within walls or attics. The force of a lightning strike can cause significant structural compromise, fracturing concrete, shattering glass, and cracking walls and foundations. Chimneys, in particular, are vulnerable to damage from the intense vibrations and heat.
Beyond direct physical destruction, lightning impacts electrical systems within buildings. When lightning strikes a structure, it can cause a massive surge of electrical energy to travel through the wiring. This overwhelming voltage can damage or destroy connected equipment and appliances, and may manifest as flickering lights, buzzing noises from devices, or visible burn marks on outlets. Such surges can also compromise the integrity of the electrical wiring itself, potentially leading to additional fire hazards if wires overheat.
Lightning also disrupts broader infrastructure, particularly power grids. Strikes to power lines can introduce massive voltage spikes into the electrical network. These spikes can propagate through the system, leading to widespread power outages and equipment failures across connected properties. The damage can extend beyond immediate outages, affecting the long-term reliability of the electrical distribution system.
Effects on Natural Environments
Lightning impacts natural environments, initiating destructive processes. It serves as a natural ignition source for wildfires, leading to widespread ecological disruption. These fires can alter landscapes, affect biodiversity, and contribute to air pollution.
Trees are especially susceptible to lightning damage. When lightning strikes a tree, the immense heat causes the water and sap within its trunk and branches to instantly vaporize into steam. This rapid expansion of steam can cause the tree to explode or split along its length, scattering wood fragments.
The ground current generated by a lightning strike can also affect the immediate environment. This current spreads outwards from the strike point along the ground surface, impacting a wider area than a direct strike. The ground current is known to be a cause of death for many farm animals, as the current travels through their bodies across the ground.
Harm to Electronics and Appliances
Lightning poses a threat to sensitive electronic devices and household appliances. Power surges are the most frequent cause of damage to electronics, often occurring even from indirect or nearby lightning strikes. These surges introduce massive voltage spikes into electrical systems, overwhelming and destroying unprotected devices. Sensitive integrated circuits found in modern consumer electronics like computers, televisions, and smart devices are particularly vulnerable to these sudden influxes of power.
Electromagnetic pulses (EMPs) generated by lightning strikes can also cause widespread damage. An EMP is electromagnetic energy that can induce voltage spikes in any electrical circuit within range, even in unplugged electronics. This induced current can lead to system crashes, data corruption, and permanent hardware damage in microprocessors and other electronic components. While direct lightning strikes to electronics are less common, they can destroy devices due to the extreme heat and current.
Damage to appliances and electronics can be instantaneous and severe, often making repair impossible. Appliances with electronic control boards, such as refrigerators and washing machines, are just as susceptible as smaller devices. Homeowners may discover damage to their electronic equipment later, as the effects might not be immediately apparent.